1. Field of the Invention
This invention relates to a support device for a packed column. More particularly the invention relates to a support device for supporting a packing material in a packed column having counterflowing gas and liquid.
2. Description of the Prior Art
Packed columns are typically used for gas absorption and for distillation. The column contains a packing material through which the liquid usually flows downwardly and the gas usually flows upwardly. The packing material may, for example, comprise Raschig rings or Pall rings.
It is often desirable to take a sidestream from the packed column, and to do so presents particular problems. In particular it is necessary to provide a support device for the packing material beneath which is situated a collection tray.
The support device permits liquid to pass downwardly therethrough to be collected by the collection tray from where it can be directed to a side of the column. A proportion of the liquid is taken from the column as a sidestream, and the remainder, if any, is fed back to the column either above or below the collection tray.
The sidestream may be fed to another part of the chemical plant, or it may be recycled to the column at a position either above or below the collection tray.
It is clear from the foregoing that two separate items (i.e. a collection tray and a support device) are needed when a sidestream is taken from a column. Furthermore, a spacing of 1 or 2 meters may be necessary between the support device and the collection tray. Thus, the provision of a sidestream in a column significantly increases capital costs. In addition, maintenance is time consuming because two separate items must be maintained.